But their relationship is apparently so strong that the report even made Pattinson's own mother believe it! "There was a magazine, with these pictures, saying I was getting married. No one ever knows what is true or what isn't," the Cosmopolis star explains. "Even my own mum called to ask me if it was true."

BlackBook's writer Joshua David Stein, notes, "It's not. At least, not yet." Stein also shares that Pattinson, 26, was pining for Stewart, 22, when he first moved to Los Angeles wrote sad love songs for her. "In fact," Rob says. "I was just trying to rip off Van Morrison."

Pattinson also admits that he's trying to get into better shape and is "on an all-liquid diet." He explains, "I had to be shirtless for a photo shoot, so I asked a nutritionist what's a diet in which you can still drink as much as you want. She said a liquid diet."

"I was so impressed with myself yesterday," he shares, "I took a pee that was four minutes long."

Another recent accomplishment for the the Twilight heartthrob? BlackBook shares he quit smoking, but now carries around electronic cigarettes.

Stewart also recently quit smoking. In May she told MTV News she gave it up, but didn't want to talk about it. "You can't acknowledge it or else suddenly . . . you can't think about it," she explained, but the live audience cheered her on for kicking the bad habit.

Sources told Us Weekly in April that Pattinson was "upset" after photos emerged of him paddleboarding wearing only swim trunks in Malibu. "He's really insecure about his shirt being off," a source said of the British star. And a source added that he stressed out about his smoking habit, explaining, "He's trying to cut back."